In-Situ Constructing C3n5 Nanosheets/Bi2wo6 Nanodots S-Scheme Heterojunction with Enhanced Structural Defects for Efficiently Photocatalytic Removal of Tetracycline and Cr(Vi)

Building step-scheme (S-scheme) heterojunctions is newly emerging to be an efficient means to get excellent photocatalysts for water pollution control. Herein, a 2D/0D S-scheme heterojunction of C 3 N 5 /Bi 2 WO 6 is synthesized by in-situ growing 0D Bi 2 WO 6 nanodots on 2D C 3 N 5 nanosheets. Photocatalytically removing tetracycline (TC) and Cr(VI) from water is employed to evaluate the activity of C 3 N 5 /Bi 2 WO 6 under visible light compared to C 3 N 5 , Bi 2 WO 6 , and their mechanical mixture. Obviously, Bi 2 WO 6 /C 3 N 5 is much more active in visible-light-driven TC and Cr(VI), meaning that a strong interaction between C 3 N 5 nanosheets and Bi 2 WO 6 nanodots is formed by in-situ growth. Such an interaction can be illustrated as the S-scheme transfer behavior of photogenerated electrons and holes which boosts interfacial charge separation, retains the optimum redox ability of photo-induced charge carriers and fosters the generation of more active species. Moreover, C 3 N 5 /Bi 2 WO 6 shows more structural defects than single C 3 N 5 and single Bi 2 WO 6 , which may endow C 3 N 5 /Bi 2 WO 6 with a better ability in the activation and photo-oxidation of TC as well as the activation and photo-reduction of Cr(VI). In a nutshell, this work gives a deeply understanding on the photocatalytic mechanism based on C 3 N 5 /Bi 2 WO 6 as well as presents a newfangled thought for developing highly efficient S-scheme heterojunction photocatalysts for water decontamination